Challenge 3: Model a Product as a Hash — Possible Solution
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127.0.0.1:6379> HSET product:200 name "Wireless Mouse" price "24.99" category "electronics"
(integer) 3
127.0.0.1:6379> HGETALL product:200
1) "name"
2) "Wireless Mouse"
3) "price"
4) "24.99"
5) "category"
6) "electronics"

WHY THIS WORKS AS AN ANSWER
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HSET product:200 followed by alternating field-name/value pairs sets
all three fields in a single command, returning 3 — the number of NEW
fields that were set (matching HSET's return behavior from this
chapter's HSET user:104 example, which returned 2 for its two fields).

HGETALL product:200 then reads back every field-value pair stored
under that one key, confirming all three fields are present with the
correct values.

Using a single hash here — rather than three separate string keys like
product:200:name, product:200:price, and product:200:category — is
exactly this chapter's comparison-box point: the product is naturally
one object with several related fields, so one hash key groups them
together cleanly, rather than scattering them across multiple loosely
related top-level keys that all happen to share a naming prefix.